Relaxant Effect of the Extracts of Crataegus mexicana on Guinea Pig Tracheal Smooth Muscle

Anti-Obesity Actions of Two Separated Aqueous Extracts From Arbutus (Arbutus unedo) and Hawthorn (Crataegus monogyna) Fruits Against High-Fat Diet in Rats via Potent Antioxidant Target

Arbutus unedo and Crataegus monogyna are widely distributed throughout the Mediterranean basin and commonly used in folk medicine against a wide range of diseases. Therefore, the present study has been designed to evaluate the anti-obesity potential of two aqueous extracts of the fruits of A. unedo (AUAE) and C. monogyna (CMAE). Male Wistar rats were supplied with a standard diet (SD), high-fat diet (HFD), HFD with the two separated extracts at the same dose (300 mg/kg, BW, p. o.), or HFD with atorvastatin-(ATOR) (2.1 mg/kg, BW, p. o.) for 12 weeks. Lipid profile and the liver and kidney linked-markers were assessed. Besides, obesity-related disorders' biomarkers were measured. AUAE, CMAE, and ATOR were observed to reduce significantly total body and organ weights following HFD-induced obese rat models. Likewise, epididymal and abdominal adipose tissue weights were noticeably decreased in HFD rats treated with both extracts and ATOR. Added to that, biochemical and metabolic changes were normalized by significant attenuation of lipid peroxidation accompanied with an increase of thiol-group concentrations and antioxidant status. More importantly, a modulation in trace element levels was revealed when compared with HFD group. Altogether, current study concluded that AUAE and CMAE could be potential candidates for the prevention and treatment of obesity and related disturbs induced by HFD.

Development of a quantified herbal extract of hawthorn Crataegus mexicana leaves with vasodilator effect

Hawthorn (Crataegus spp.) has been used for the treatment of several heart diseases and hypertension. The studies carried out on several hawthorn species have led to the development of standardized extracts useful in the cure of mild chronic cardiac diseases.

In Mexico, the most common Crataegus species are C. mexicana and C. gracilior. Decoctions prepared from the fruits and leaves of these species have been employed to the treat respiratory diseases, tachycardia and to improve coronary blood flow. Considering that to date there are no reports of the use of Mexican Crataegus species to treat cardiovascular diseases, we propose an analytical method to obtain a quantified extract of Crataegus mexicana leaves for the development of a standardized extract with therapeutic value in cardiovascular diseases as an alternative source to the extracts obtained from Crataegus species of European and Asian origin.

Therefore, the aim of this study was to obtain an extract prepared from C. mexicana leaves with the highest vasodilator activity to select the optimal chemical marker to stablish and validate a reversed-phase high-performance liquid chromatography (RPHPLC-DAD) analytical method for obtaining a quantified extract with vasodilator effect.

The results obtained from the analytical method validation, which was carried out according to the guidelines stablished in the Eurachem Guide and the ICH guidelines proved that the RPHPLC-DAD method we developed was specific, precise, accurate, and showed good linearity over the concentration range of 3 – 21 µg/ml for (-)-epicatechin and rutin, which were selected as chemical markers.

Phenolic Compounds in Mesoamerican Fruits-Characterization, Health Potential and Processing with Innovative Technologies

Diets rich in phenolic compounds have been associated to reducing the risk of metabolic syndrome and its derived disorders. Fruits are healthy components of the human diet because of their vitamin, mineral, fiber and phenolic profile. However, they have a short shelf-life which is limited by microbiological growth and enzymatic activity. Innovative preservation methods such as high hydrostatic pressure, pulsed electric fields, ultrasound, microwave, cold plasma and ultraviolet light have become popular for the processing of fruits because they can preserve nutritional quality. In this review, the phenolic profile and health potential of 38 Mesoamerican fruits were assessed. Phenolic compounds were classified based on their contribution to the diet as flavonoids, phenolic acids, tannin, lignins and stilbenoids. Due to this composition, fruits showed a wide range of bioactivities which included anti-inflammatory, anti-diabetic, anti-hypertensive and anti-obesity activities, among others. Phenolic content in fruits submitted to innovative food processing technologies depended on parameters such as enzymatic activity, antioxidant capacity, microstructure integrity and cell viability. Innovative technologies could increase phenolic content while assuring microbiological safety by (i) promoting the release of bound phenolic compounds during processing and (ii) inducing the synthesis of phenolic compounds by activation of phenylpropanoid pathway during storage.

Vasodilator Activity of Compounds Isolated from Plants Used in Mexican Traditional Medicine

Arterial hypertension is one of the main risk factors in the development of cardiovascular diseases. Therefore, it is important to look for new drugs to treat hypertension. In this study, we carried out the screening of 19 compounds (triterpenes, diterpenes, sesquiterpenes, lignans, and flavonoids) isolated from 10 plants used in Mexican traditional medicine to determine whether they elicited vascular smooth muscle relaxation and, therefore, could represent novel anti-hypertension drug candidates. The vasorelaxant activity of these compounds was evaluated on the isolated rat aorta assay and the results obtained from this evaluation showed that three compounds induced a significant vasodilatory effect: meso-dihydroguaiaretic acid [half maximal effective concentration (EC₅₀), 49.9 ± 11.2 µM; maximum effect (Emax), 99.8 ± 2.7%]; corosolic acid (EC₅₀, 108.9 ± 6.7 µM; Emax, 96.4 ± 4.2%); and 5,8,4′-trihydroxy-3,7-dimethoxyflavone (EC₅₀, 122.3 ± 7.6 µM; Emax, 99.5 ± 5.4%). Subsequently, involvement of the NO/cyclic guanosine monophosphate (cGMP) and H₂S/ATP-sensitive potassium channel (K_ATP) pathways on the vasodilator activity of these compounds was assessed. The results derived from this analysis showed that the activation of both pathways contributes to the vasorelaxant effect of corosolic acid. On the other hand, the vasodilator effect of meso-dihydroguaiaretic acid and 5,8,4′-trihydroxy-3,7-dimethoxyflavone, partly involves stimulation of the NO/cGMP pathway. However, these compounds also showed an important endothelium-independent vasorelaxant effect, whose mechanism of action remains to be clarified. This study indicates that meso-dihydroguaiaretic acid, corosolic acid, and 5,8,4′-trihydroxy-3,7-dimethoxyflavone could be used as lead compounds for the synthesis of new derivatives with a higher potency to be developed as drugs for the prevention and treatment of cardiovascular diseases.

Aortic relaxant activity of Crataegus gracilior Phipps and identification of some of its chemical constituents

This study focused on the assessment of the vasorelaxant activity of the organic and aqueous extracts obtained from leaves and fruits of a Mexican hawthorn (Crataegus gracilior) on isolated rat aorta, and on the purification and identification of some of their secondary metabolites by the use of chromatographic and spectroscopic techniques. The results obtained showed that the methanol extract has a significantly more potent and effective vasorelaxant effect than the other tested extracts, with an EC₅₀ = 8.69 ± 4.34 µg/mL and an E_max = 94.6% ± 11.30%, values that are close to that of acetylcholine, the positive control. From the same extract, two major triterpenes were isolated and identified as ursolic and corosolic acids by comparison of their experimental NMR spectroscopic data with those reported in the literature. Chlorogenic acid, rutin, quercetin, kaempferol and (+)-catechin were also identified using HPLC coupled with PDAD. All these compounds have already been proven to possess on their own antihypertensive effect and other benefits on cardiovascular diseases and they can support, at least in part, the traditional use of this plant species.

A review of the chemistry of the genus Crataegus

Since the 1800s, natural health products that contain hawthorn (Crataegus spp.) have been used in North America for the treatment of heart problems such as hypertension, angina, arrhythmia, and congestive heart failure. Traditionally, Native American tribes used hawthorn (Crataegus spp.) to treat gastrointestinal ailments and heart problems, and consumed the fruit as food. Hawthorn also has a long history of use in Europe and China for food, and in traditional medicine. Investigations of Crataegus spp. typically focus on the identification and quantification of flavonoids and anthocyanins, which have been shown to have pharmacological activity. The main flavonoids found in Crataegus spp. are hyperoside, vitexin, and additional glycosylated derivatives of these compounds. Reviewed herein are the botany, ethnobotany, and traditional use of hawthorn while focusing on the phytochemicals that have been reported in Crataegus species, and the variation in the described chemistry between individual species.